passt/tcp_vu.h, branch bug209 Plug A Simple Socket Transport flow, treewide: Promote priority of selected flow-linked messages 2026-06-22T07:13:46+00:00 David Gibson david@gibson.dropbear.id.au 2026-06-19T15:26:25+00:00 74863b01d304beda59d7a7bc9cfa887683fedd95 Most of out flow specific log messages are debug level for fear of flooding the logs, even when they report real error conditions that might be off significance. Now that we have the mechanisms for log message rate limiting, we can do better. Promote many flow related messages to warning or error level, with rate limiting. While we're there add ratelimiting to a handful of existing warning or error level messages. They general heuristic is to promote messages that report a failure which is not something that should be triggered by the guest doing something weird. This mostly means failures from socket operations we expect to be legitimate. Adding the ratelimiting means plumbing the 'now' timestamp through much more of the code, hence the large churn. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> 
Most of out flow specific log messages are debug level for fear of flooding
the logs, even when they report real error conditions that might be off
significance.

Now that we have the mechanisms for log message rate limiting, we can do
better.  Promote many flow related messages to warning or error level, with
rate limiting.  While we're there add ratelimiting to a handful of existing
warning or error level messages.

They general heuristic is to promote messages that report a failure which
is not something that should be triggered by the guest doing something
weird.  This mostly means failures from socket operations we expect to be
legitimate.

Adding the ratelimiting means plumbing the 'now' timestamp through much
more of the code, hence the large churn.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
tcp: Merge common sequence logic from tcp_{buf,vu}_data_from_sock() 2026-06-16T21:49:39+00:00 David Gibson david@gibson.dropbear.id.au 2026-06-15T08:18:31+00:00 751a6f1d3288334afd3eda687e46968a5b5861bd tcp_buf_data_from_sock() and tcp_vu_data_from_sock() start with some identical logic to compute the amount of data from the socket that has already been sent to tap but not acked. Replace it with a single copy in their common caller tcp_data_from_sock(), passing the already_sent amount in as a parameter. This does mean that we now execute this logic in the VU case even if the queue is not active. The logic is still valid in this case, and we don't need to worry too much about wasting cycles in this edge case. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> 
tcp_buf_data_from_sock() and tcp_vu_data_from_sock() start with some
identical logic to compute the amount of data from the socket that has
already been sent to tap but not acked.  Replace it with a single copy in
their common caller tcp_data_from_sock(), passing the already_sent amount
in as a parameter.

This does mean that we now execute this logic in the VU case even if the
queue is not active.  The logic is still valid in this case, and we don't
need to worry too much about wasting cycles in this edge case.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
vhost-user: add vhost-user 2024-11-27T15:47:32+00:00 Laurent Vivier lvivier@redhat.com 2024-11-22T16:43:34+00:00 28997fcb29b560fc0dcfd91bad5eece3ded5eb72 add virtio and vhost-user functions to connect with QEMU. $ ./passt --vhost-user and # qemu-system-x86_64 ... -m 4G \ -object memory-backend-memfd,id=memfd0,share=on,size=4G \ -numa node,memdev=memfd0 \ -chardev socket,id=chr0,path=/tmp/passt_1.socket \ -netdev vhost-user,id=netdev0,chardev=chr0 \ -device virtio-net,mac=9a:2b:2c:2d:2e:2f,netdev=netdev0 \ ... Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: as suggested by lvivier, include <netinet/if_ether.h> before including <linux/if_ether.h> as C libraries such as musl __UAPI_DEF_ETHHDR in <netinet/if_ether.h> if they already have a definition of struct ethhdr] Signed-off-by: Stefano Brivio <sbrivio@redhat.com> 
add virtio and vhost-user functions to connect with QEMU.

  $ ./passt --vhost-user

and

  # qemu-system-x86_64 ... -m 4G \
        -object memory-backend-memfd,id=memfd0,share=on,size=4G \
        -numa node,memdev=memfd0 \
        -chardev socket,id=chr0,path=/tmp/passt_1.socket \
        -netdev vhost-user,id=netdev0,chardev=chr0 \
        -device virtio-net,mac=9a:2b:2c:2d:2e:2f,netdev=netdev0 \
        ...

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: as suggested by lvivier, include <netinet/if_ether.h>
 before including <linux/if_ether.h> as C libraries such as musl
 __UAPI_DEF_ETHHDR in <netinet/if_ether.h> if they already have
 a definition of struct ethhdr]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>